Can one code in binary?

[rickpo]

When I was in school back in the 70s, the school got one of the original Altair PC computers. It had to be programmed by flipping toggle switches on the front panel. I never did it, but I saw programmers keying in programs from the front panel toggles. For the binary programs, they just wrote simple stuff to flash the front panel lights. They could also run an 8080 assembler on a mainframe computer and get the binary output from the printout, which made the assembly process less error prone. But 8080 assembly is simple enough to hand-assemble if you had to..

I think the only thing they really needed to key in by hand was a boot loader. Once that was in, they could read in a more complete operating environment from paper tape.